Compensation circuitry and method for amplifiers driving large capacitive loads

摘要

An operational amplifier (10) capable of driving a capacitive load (C_LOAD) and/or a resistive load (R_LOAD) includes a first gain stage (2) having an output coupled to a high impedance node (3) and a second gain stage (5) having an input coupled to the first high impedance node. A gain reduction resistor (R_D) and an AC coupling capacitor (C_D) are coupled in series between the high impedance node and a reference voltage. A Miller feedback capacitor (C_M) is coupled between an output conductor (7) of the second gain stage and the high impedance node. The output of the second gain stage may be coupled to the high impedance node by a cascode transistor (M_CASCODE).